In certain types of devices it was known to provide timed, actuated locking mechanisms using electrical or clock mechanisms. Such devices are disclosed in U.S. Pat. No. 3,800,522, granted Apr. 2, 1974 to Beharelle; U.S. Pat. No. 2,210,186, granted Aug. 6, 1940 to Ross; and U.S. Pat. No. 2,145,314, granted Jan. 31, 1939 to Murtagh.
Heretofore it was known to provide elaborate electronic systems for limiting access to a lobby. Systems of this nature are disclosed in U.S. Pat. No. 3,484,561, granted Dec. 16, 1969 to Matthews.
A security problem exists today, however, for people entering the vestibule of a building who are accosted or mugged by intruders because such people are unable to open the lobby door rapidly. Very often muggers follow the tenants to the building and wait while the tenant fumbles for the key to the lobby door.
The aforesaid prior art does not suitably address this problem.
Now there is provided by the present invention a safety lock construction and combination which provide the tenant with the ability to readily lock out unwanted intruders from the building vestibule for a predetermined period of time, while the tenant gains access to the lobby of the building, thus foiling any mugging attempts by the intruder.